Your Wednesday Morning Briefing Special Edition: Hurricane Florence

Hurricane Florence remains a powerful category 4 hurricane with winds sustained as high as 130 mph as the storm continues to grow in size, with it going through yet another eye-wall replacement cycle this morning. With just over 24 hours to go before we see initial impacts from Florence along the North Carolina coastline, we’re beginning to see some of our worst fears for this storm come true.

In this special edition of your Wednesday Morning WeatherOptics Briefing, we’ll be going over all-things Florence as we try to nail down the exact impacts before they happen.

We’re beginning to get an idea of just how large and powerful Florence is this morning when compared to the southeast coastline of the United States. The first outer band of Florence located hundreds of miles northwest of the storms center, has nearly reached the outer banks of North Carolina. This is a testament to just how massive she is.

The bad news is we think Florence could grow even larger before impacting the Carolinas, possibly expanding both its outer core and eye wall. This means that areas well outside of the immediate impact zones will still feel very strong effects.

What Has Changed Over the Last 24 Hours:

Models remain very locked in on a final solution of a landfall, or close landfall, to Wilmington NC. However, there has been a very important and small shift. Rather than slowing down or stalling, making landfall, and then slowly moving inland and weakening, guidance is now in strong agreement that after initial impact, Florence will remain just offshore and move down the southeast coastline. This would be the worst case scenario, as not only would Florence maintain its strength for days longer, but it would slowly drift down the coast and hit town by town from Wilmington NC to Charleston SC to potentially as far south as Savannah GA now. We hate to use this comparison, but somewhat similar to what Harvey did last year when it stalled just before landfall at the Texas coastline.

Above is the 00z GFS, which is now in complete agreement with the majority of other guidance models. It shows an extreme slowdown just before landfall on the coast of North Carolina. Notice on Friday and Saturday there is almost no movement at all. That stalling pattern warrant days of extreme rain as well as wind and a storm surge pounding the same 100-200 miles of land over and over again. To put it plainly, the outcome of this is absolute devastation. Following this we see a slow drift down the coastline through Sunday and into early next week, literally hitting every area along the coastline down to the Georgia/ South Carolina border. This allows Florence to maintain her strength and size by continuing to feed off the warm waters of the Atlantic, while at the same time slamming these coastal towns. Eventually the storm will finally move inland and weaken, but this likely won’t occur until Monday of next week.

Worst Case Senario:

We don’t think the models are wrong in their latest depictions of Hurricane Florence’s track, which unfortunately means this worst case scenario is more likely than not. This would mean that cities from south of Nags Head and the Outer Banks all the way down to Savannah, GA could be looking at “extreme conditions” for hours, perhaps even days.

What does “extreme conditions”mean? Wind gusts 115-130+ mph, storm surge that could surpass 10-15 feet during the storms peak, and rainfall 10-20+ inches. These kind of conditions by themselves would be devastating, a total catastrophe for some localized areas near the coast. However, the fact that we’ll be seeing multiple days of these conditions means it will likely be even worse. Locations that see 18-24 hours + of winds gusting over 100 mph, rainfall rates of 3-5 inches per hour, and an extreme storm surge is something that even we’re having a hard time grasping. This is why we are taking Florence so seriously and urging that people head the warnings to leave.

The devastation will likely merit months of cleanup and recovery. There will be the total loss of some structures and areas where water will take weeks to recede from. With such a large system as well, there are going to be “secondary severe conditions” for regions outside of the immediate impact zone. This includes damaging winds, and worse, more extreme flooding.

You can see last night the 00z GFS showing a large swath of 10-20+ inches of rainfall within the area the storm will make landfall. But even well outside of that zone we see 6-10+ inches extending all the way back into the interior Carolinas and the southern end of the Appalachians. This part of the storm cannot be underestimated, as flooding will no doubt be a major issue for more than just the coastline.

We’ll have a more detailed update later today on Florence and potential specific impacts in terms of maximum wind gusts, storm surge, rainfall, and more. Check back then, and be sure to subscribe to the WeatherOptics Morning Briefings so we can send you all-things weather right to your inbox every Wednesday and Friday morning for free.

Currently leads business development and forecasting across all sectors and is the Founder and CEO. Pecoriello founded WeatherOptics in 2010 as a blog called, Wild About Weather, which quickly gained a following. He also launched an app in 2013 called, Know Snow, designed to accurately forecast the chances of school closings.